Glowing blue orb about 4 feet diameter hovers above ground.

One night in 1975 I was trying to go to sleep when every dog in the neighborhood was barking or howling and then my dog who sleeps with me began to growl.  I got up to see if there was something outside.  I went out my back door and walked around to the corner of the house.  My bedroom extends out in an l shape.  As I turned the corner I could see a blue glow.  When I could completely turn the corner I saw a round object about 3 or 4 feet diameter floating off the ground about 2 feet.  The object had no visible material, just the blue glow . I would call it a blue L E D .  At the time in 1975 I didn’t know about L E D.  it was visible for only about 20 seconds and I was shocked.   This was in the country on a gravel road with empty lots on both sides and a pasture in back.  No street lights.  My dog and I went back to bed.  The next morning I called a tv station and asked if they had heard of anything unusual in Timbercrest.  He said no, why?  I hung up!  It disappeared after about 20 seconds.